80 lines
1.8 KiB
C
80 lines
1.8 KiB
C
/**
|
|
* @file lv_utils.c
|
|
*
|
|
*/
|
|
|
|
/*********************
|
|
* INCLUDES
|
|
*********************/
|
|
#include <stddef.h>
|
|
|
|
#include "lv_utils.h"
|
|
|
|
/*********************
|
|
* DEFINES
|
|
*********************/
|
|
|
|
/**********************
|
|
* TYPEDEFS
|
|
**********************/
|
|
|
|
/**********************
|
|
* STATIC PROTOTYPES
|
|
**********************/
|
|
|
|
/**********************
|
|
* STATIC VARIABLES
|
|
**********************/
|
|
|
|
/**********************
|
|
* MACROS
|
|
**********************/
|
|
|
|
/**********************
|
|
* GLOBAL FUNCTIONS
|
|
**********************/
|
|
|
|
/** Searches base[0] to base[n - 1] for an item that matches *key.
|
|
*
|
|
* @note The function cmp must return negative if its first
|
|
* argument (the search key) is less than its second (a table entry),
|
|
* zero if equal, and positive if greater.
|
|
*
|
|
* @note Items in the array must be in ascending order.
|
|
*
|
|
* @param key Pointer to item being searched for
|
|
* @param base Pointer to first element to search
|
|
* @param n Number of elements
|
|
* @param size Size of each element
|
|
* @param cmp Pointer to comparison function (see #unicode_list_compare as a comparison function
|
|
* example)
|
|
*
|
|
* @return a pointer to a matching item, or NULL if none exists.
|
|
*/
|
|
void * _lv_utils_bsearch(const void * key, const void * base, uint32_t n, uint32_t size,
|
|
int32_t (*cmp)(const void * pRef, const void * pElement))
|
|
{
|
|
const char * middle;
|
|
int32_t c;
|
|
|
|
for(middle = base; n != 0;) {
|
|
middle += (n / 2) * size;
|
|
if((c = (*cmp)(key, middle)) > 0) {
|
|
n = (n / 2) - ((n & 1) == 0);
|
|
base = (middle += size);
|
|
}
|
|
else if(c < 0) {
|
|
n /= 2;
|
|
middle = base;
|
|
}
|
|
else {
|
|
return (char *)middle;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/**********************
|
|
* STATIC FUNCTIONS
|
|
**********************/
|